Assiqnob to naam



Feb. 7, 1928. Re. 16,870

- 'r. H. NAKKEN IEANS FOR TRANSFORIING LIGHT IMPULSES INTO ELECTRIC CURRENT IMPULSES Original Filed Nov. :5, 1920 4 Sheets-Sheet 1 7th. MM!!!- INVENTOR ATTORN E Feb. 7, 1928.

T. H. NAKKEN MEANS FOR TRANSFORIING LIGHT IMPULSES INTO ELECTRIC CURRENT IIPULSES 4 Sheets-sheaf. 3

Original Filed Nov. 3, 1920 Zil- IVAIKE/V.

, INVEN'I'OR 2 5 BY f ATTORN Feb. 7, 1928. Re. 16,870

I T. H. NAKKEN IBANS FOR TRANSFORMING LIGHT IIPULSES INTO ELECTRIC CURRENT IIPULSES Original Filed Nov. :5, 1920 4 Sheets-Sheet 4 mwzzvron 77/5000/705 ll. A/A IKE/l.

- I ATTORNEYS.

Ren al-eh. 7, 192a;

Nrrsu STA PATENT omen-1;.

rmaononus moan NAKKEN, or mass! crr'v, imw was, assmnon 'ro mm.

L002] VBNNOOTSOHAP NEDEBIQLNDSCHE LUMIHOTBON m'rscmma, OI norrmanna, NETHERLANDS, A COMPANY aunts Ion rmsronmme ueirr mrunsns nrro unaware-comm mums.

flrlglnal No. 1,688,070, dated January 6, 1925, Serial No. 481,848, filed November. 3, 1920. Application for reissue filed January 8,

Heretofore all attempts to transform light impulses into electric current impulses have functioned upon the principle of varying the dynamic flow of'an electric current through 5 a circuit including a source of current, a light Sensitive cell and a translatin device all in series with each other, the lig it sensitivie cell being regarded and functioning in a manner similar to a microphone for modl0 ulating or varying the dynamic flow of cur.- rent responsively to sound variations. Man

- light sensitive cells per so have been capable of controlling only substantlally negligible variations of such dynamic flow.

1 Before my invention the seleniumcell ractically has been the only practical means ibr transforming light impulses into electric current impulses. This cell has the limitation of sluggishness or inertia and 1n-' 2 capability of being adjusted once it has been completed. It is moapable of responding. at

all to light variations much more rapid than 1000 per second. Such cells are of no value for the solution of quite a numberv of highly important problems such as the talking film, the rapid action telephotography, television, and so forth.

My invention is based upon. the comb ning of two inherent characteristics, one in- 3 herent characteristic of a photo-electric body and one inherent characteristic of the thermionic relay, by which latter I mean an apparatus comprising an electron emitting cathode, a grid and a plate in thermionic cooperative array, with a plate circuit having a source of direct current, the strength of current flow in which circuit is' controlled by the-potential of said grid. Mm" me als emit orshed electrons'when ex V dinary light andothers when exposed; to ultra violet rays. This so-oalled photo-electric or Hallwaek efiect is'very strong with the alkaline. metals, and-with their amalgame. The emission or sheddingof the electrons time depends upon the intensity of the light- 1' l and the area of the surface of the body to li'ghhsomewhen exposed to orfrom such bodies is instantaneous in a response to the impingement of the light. The number of electrons emitted p'er umt of 1937. Serial I0. 158,980.

been slowly discharged into an indicator under the influence of star-light acting over a long period of time, to indicate the amount of light received from such star.

On the other hand, the characteristic of the photo-electric body which I utilize in my nvention is the instantaneous chan e of static potential of the photo-electric body occasioned by the instantaneous shedding of electrons in response to received light. The characteristic inherent in the thermionic relay which I utilize in my invention is that relatively. slight static potential changes of the grid effect unexpectedly large but corresponding fluctuations in'the strength of a dynamic current flow. in the plate circuit. My invention therefore contemplates the association of the grid-action of a thermionic relay with the potential functioning of a photo-electric body in response to light vanations.

For the practical-carrying out of m invention it is also necessary that a source of charge be provided in a suitable manner to reestablish and tend to maintain normal upon the t e thereifect in shedding electrons as is possible. It is of course to be understood that the need.

for this rapidity of recovery of normal po tential and-normal charge of these elements is dependent only upon the rapidity of the light fluctuations to be translated. I therefore understand that there are various de-.

grees towards which perfect functioning may approach. I have contemplated, at least theoretically, that for the most nearly perfect combination, such means prise a thermionic relay in *which the id was also a photo electricbody shedding "e ec-j trons instantaneously in response to impinging light and instantaneousl recovering them after the removal of lig t to produce a normal charge lar y, out of the same .field of electrons emp oyed for operating the thermionic relay.

As a rule, the electron relays is dependent largely upon heat citation of a cathode tosuch. a deal? a temperature is required higher,

exthat It is preferable that this would comfield in thermionic body,

irompatible with a solid state for most of the satisfactory photo-electric bodies. I-tlicre- Zorc contemplate as ireferablc a. physical separation between t e 'potcntia-l varying photo electric body and t 'e potential vary ing grid of the relay, so that I can fabricate the grid out of the most suitable high temperature resisting metal and the hoto-electric body of the most suitablelig t responsive material, even such that is meltable at a low tem rature and by its separation be maintain if necessary, at a lower temperature by artifical cooling.

All that is necessary to be done is to provide. an electric connection between the photo-electric body and the grid of such a character as will effect an instantaneous potential change of the grid in response to a controlling potential change of the photoelectricbody (This usually means a low resistance conductive connection.) and also to provide a stabilizin source tending to maintain a negative charge upon charge upon said photo-electric body.

The shedding of electrons by a photo-electric body causes a reduction of its negative charge and. potential. If the electrons shed 'by a photo-electric bod in response to light are caused to co lect upon an electrode, obviously the negative charge and potential of such "electrode increases. I therefore contemplate as within the scope of my invention the utilization of this consequent increase in negative charge upon such an electrode in combination with the grid of a thermionic relay. In fact, I claim broadl the combination of any the potential of which increases or decreases due to photo-electric action, with the grid of a thermionicrelay and so associated with any charge either positive or ne tive as to efpotential confect a resumption of norma the light has dition after the effect of ceased.

The most ractical conditions for the maintenance 0 sensitive photo-electric effect on a photo-electric body believe to be provided b enclosing the photo-electric body in a bul through which the action' of light to which the device is to be nsive can pass freely content has been evacuated to eflect a substantially perfect vacuum for a hard condition or at least rarified and with the residual gas a neutral gas such as helium, for a soft condition. In other words provision should be made to provide a cooperative atmos here. I also prefer that the photo-electric body be associated with an electrode for collecting the emitted electrons also 'within the evacuated bulb. I have found that a satisfactory source for the charging of the photo-electric body is an electron emitting cathode such as an incansuitable recovering source of and from which bulb the gaseous argon, etc.,

descent filament, although, as will hereinafter he described, certain circuit connections render negative charging by free electrons unnecessary because the necessary connections of batteries incidental to the circuit, such as the so-called B battery of the plate circuit provides an adequate source of charge for the photo-electric body.

I have found, in effect, that the ways and modifications of applying my principle of transferring instantaneously the effect of static potential changes of a body functioning under the influence of photo-electric phenomena to the controlling element or grid of a thermoinic relay are very many, too numerous for complete description and illustration. I have therefore, in the following specification, described in detail illustrative ways and circuits, perhaps in error leaning towards an illustration and description of the more nearly theoretically perfect arrangements, rather than to the more obvious. The above and further objects of my invention will be apparent from the illustative embodiments described more in detail in the following specification in connection with the accoi anying drawings which form a part hereo and in which like characters (losignate corresponding parts in the several figures. It is to these illustrative embodiments that my claims are directed merely for purposes of illustration and not limitation. In the drawings Fig. l is a diagrammatical side view of means forming a. part of my invention; Fig. 2, is a diagrammatical view in top plan, showing the photo-electric body associated with a source of charge and connected with a potential indicator. Fig. 3, Fig. 4, Fig. 5, and Fi 6 are elevations similar to Fig. 1 illustrating various forms of apparatus useful in connection with my invention; Figs. 4 5, and 6 are res ectively diagrammatical views in top plan 0 the corres nding elevations shown in Figs. 4, 5 an 6 drawn in a manner similar to the diagrammatical top plan of Fig. 2; Fig. 6 is the circuit diagram of one assemblage of means embodying my invention in which the photo-electric cathode is connected with the grid; Fig. 6 is another circuit embod ing my invention in which the anode of tie photo-electric couple is connected with the grid; and Fig. 5} in which the anode of the photo-electric couple is directly connected with the plate.

In all figures; 1 is the glass or other suitable bulb which may be fully exhausted or filled with neutral gas,such as helium, argon, etc., under low pressure. If the bulb is fully exhausted it is called hard, and if it is not, it is called soft. 2 is a cathode capable of emitting electrons and is shown in all figures in the form of a filament capable of being heated, to incandescence if necessary, by the passage therethrough of 18 another circuit diagram variable resistance 8. 3 1s a photo-electric plate, for instance of rubidium, hereinafter to be termed body, photo-electric body, cathode bod 4 an 5 are the contactpins of the, fi ament.- 6 is a contact pin for When the filament 2 (see Fig. 2) is brought to incandescence owing to its connection with battery 7 and regulating resistonce 8, the filament at once emits electrons, part of which reach the cathode body, 3.

is cathode body 3 will hereby be negatively charged until a maximum is attained, and an equilibrium established, when the source of electrons will absorb as manv electrons per unit of time as it emits. his charge upon the cathode body, although it is static, is a reality and can even be read as to its degree on a' calibrated electroscope such as the electroscope 9 in Fig. 2 connected through a wire 10 with the cathode body The leaf 11 of the electroscope will deflect and remain stationary in a given position.

It now the body 3 is exposcd to light. as by causing the same to shine upon it, it will instantaneously shed or emit a given number of electrons per unit of time. The kind of influence of the stream of electrons outflowing from the source of electrons here depicted, namely. the cathode 2 is such that a sufliciently high rate of influx of electrons to the cathode body 3, or in other words, a sufliciently hi h rate of negative charging of said oath e body 3 does not take place to make up for the 'rate of loss of electrons from this cathode body 3 when subJected to light. Therefore. the potential of the cathode body 3 drops and any instrument such as the electroscope 9 suitably linked therewith assumes a corresponding change in the resent instance in Fig. 2, the leaf 11 moves iack by gravity through a certain (llS- 'tanee. Vl'hen the light source is removed the original condition as to static potential is instantaneously restored. Probably the speed of restoration is augmented by the fact that at the instant when light ceases to shine upon the cathode body it is free to receive and does receive a charge not only from the source of electrons 2 but from free electrons just liberated from that body by the action of the light.

In fact, I have found that, owing to the presence of free electrons in the co-operating atmos here about the cathode body, this 'r-athodia body cannot sufier from-so-called fati e, such as is the case with the selemum cell. That is to say, said cathode body is always in condition for instantaneously emitting electrons and varying its potential in response to like "ariations, thereupon.

Figs. 3 to 6 illustrate the apparatus, which are constructed in accordance with the inven tion and which, as later to be described, are

ad:- nted to transform potential variations of the photo-electric cathode body into electric current impulses which, in their turn may be transformed through any 41 in an arbitrary manner into other forms of energy. In Fig. 3, the body 3 is rforated,'a plate 12 being rovided within the bulb 1 and connected with a contact in 13. Intermediate between 'filamcnt 2 an plate 12 is the photo-electric cathode body 3.

If now the pole of a battery 40 of say 4Q to 100 volts (see Fig. 3-A) is connected with contact 13, and thence to plate 12, its pole being connected with either lead 4 or 5 of the filament 2, then the latter when lit to incandescencc by its battery 7 will cause a current to pass through this plate circuit. This plate circuit is shown only diagrammatically, and only for the purpose of illustrating connections with the apparatus, and

not to exclude any of the well known adjuncts of a plate circuit. 'The amount of this so-called plate current de nds upon the potential of the body 3, an slight variations of this potential will entail comparatlvely great vvariations of the plate current. This phenomenon need not be explained in detail because it is that characteristic of the vacuum valve or electron rela .in which slight variations of the potentia of the rid have this efiect on the; plate current an in the instance now being described the body 3 is functioning'as a. grid. But in this instance the body 3 is also functioning as a photo-electric body and its charge or potential is directly controlled by the'li ht impulses. These light impulses themse ves' effect the emitting or shedding from this combination thingph oto-el ectrie body and grid-of various numbers of electrons. in proportion to the light impulses.

This embodiment of my invention therefore efiects a transformation oflight impulses into substantial electric current impulses in the plate circuit by means reduced to its simplest terms, a 3-element combination structure in which one of the elements has a dual nature and a dual function, that is, the combination grid body 3.

This construction is theoretically perfect in that both the (photo-electric body and the grid are one an as one are located in the field between the cathode and the plate of the electronic relay, but there is a practical defect presently to be described. In fact, substantially the same theoretical perfection may be obtained even though the photoelectric body and the grid as one combine tion thing are not located between the filament and the plate, provided that the distance to the filament from this combination thing is smaller than the distancebetwcen the filament and the plate 12.

1o suitable device other constructions.

It is possible that the potential of the body .3 may attain such a igh value as to render it advisable. to provide for a leakage resistance 42, which 18 shown in Fig. 3' connected in the usual manner.

The disadvantage referred to above of a practical character for this theoretically good construction is primarily that photoelectric bodies as a rule are damaged by heat and as a rule heat is employed to excite the electron discharge from the cathode 2. If the distance from the cathode 2 to the body 3 is too small, .the latter may be damaged by the heat of the former and in order to obviate this inconvenience I may use such for example, as those shown in Figs. 4 to 6. In such constructions the cathode body 3 may be placed at a distance from the cathode 2.

The cathode body 3 may even be laced near the wall of its closing bulb so t at it may be artificially cooled if necessary by means of a suitable fan, which would have been impossible with the unitary apparatus shown in Fig. 3.

Referring now particularly to Fig. 4 and with it being understood that what I have heretofore explained in regard to batteries, circuits. and leakage resistance, etc., is still applicable, in order that the increase in distance between cathode filament and photoelectric body may not interfere with the proper effect, I connect said photo-electric body 3 through a wire 15 with'a heat resistlng metallic member 14, the latter 'to serve in this case solely as the grid of a thermionic valve, while the former, the body 3, has placed upon it the segregated duty of functioning as a photo-electric body. It

will be understood that this apparatus func-.

tions in quite the same manner as that illustrated in Fig. 3, but it has the great advantage that the grid member 14 may now be made of metal havinga-high fusing point' as is customary in the fabrication of electron relays for the grid construction. I have illustrated one form of this physical separa tion of the body 3 from the grid 14 in Fig. 4 as to one form of its physical embodiment and dia rammatically in Fig. 4, as to its electrica' functioning. In these figures I have found it convenient to designate the functioning means shown in the form of the connecting wire 15 as a link means associating said body 3 and said grid 14 and adapted to impart tential variations to said grid corresponding to those which take place on said body.

Another embodiment of the invention is shown in Fig. 5 in which the photo-electric cathode body 3 here is made in the shape of a concave mirror, in the focus of which is .placed a small metal part. 16 hereinafter called the anode of the photo-electric couple comprising the photo-e ectric cathode body more anode allows of quite a number'of diflerent connections while maintaining the physical separation between the photo-electric couple and the elements functioning as a thermionic valve. Some of these different connections will now be described-more in detail, while others will be obvious from those described.

(a) See Fig. 6. Assumin the cathode body 3 to'be connected througl i suitable link means such as the wire 15 with the grid and the anode 16 through wire 17 with the cathode 2,' it will be understood that electrons shed from said body 3 will reach the anode 16 to flow back through wire 17 to the cathode 2. The strength of this current is limited by the actual rate of electron emission from the photo-electric body 3 and m consequence is infinitesimal, but fortunate- (liy the functioning of the apparatus is not ependent uggn thls infinitesimal return flow of electrons cause of the fact that in order for them to have left the cathode body 3, and because further of the fact that the recharging influence upon the body 3 is insufliclent, a substantial lowering of the negative potential of the body 3 takes place, which in turn has its effect through the link means 15 upon the grid 14. It is the change of potentia of the grid 4 responding to the change of potential of the body 3 which controls the strength of the appreciable current flow in the plate circuit from plate 12 supplied by battery 40.

(6) See Fig. 6". The circuit described in connection wth Fig. 6' above may be reversed by connecting the cathode body 3 through a wire 18 with the filament or cathode 2 and the anode 16 through a suitable link means such as the wire 19 with the grid 14. In this circuit the opposite effect will be obtained. The shedding of electrons from the photo-electric body 3 decreases the potential of the anode 16, the effect of which is imparted to the grid 14. This in turn makes the usual current response in the platecircuit 50.

(a) See Fig. 6. body 3 is connected through wire 15 functionin as a suitable link means with grid 14 an the anode 16 is connected through wire 20 with the plate 12, then, owing to the emission of electrons from the body 3 due lit; light 1mpulses,'the following will take p ace:

1. The potential of the grid will he reduced, that is, it will have a smaller negative charge and in accordance with the usual functioning of my invention the strength of thermionic relay a greater number of electrons reach the plate directly.

If the photo-electric necessarily asoeiated' 2, The provision of this 2. Whatever electrons emitted from the body 3 reach the anode 16 are added to the tion with Fig. 6,may be reversed by connecting the body 3 through wire 21 with the.

plate and the anode through wire 19 with the grid so that the opposite effect will then be realized. This circuit, however, is of importance only with such amplifying devices as those in which the filament emits positive articles instead of electrons. Such devices ing extremely rare, little emphasis is placed upon the circuit.

(e) Assuming the body 3 not to be connected with any of the other elementsand the anode 16 to be connected through wire 19 with the 'd 14, then the electrons emiti ddy will be collected by the charge and to effect a consequent increase of the negative charge of the grid 14. The electronic relay will then function according to its nature and there will be a decrease of substantial amount'in the current through the-plate circuit 50. This circuit is interesting in that it is the only one ofcircuits which is dependent 'for its functioning solely upon the reception of free electrons by the photoelectric body 3 for the recovery of its normal negative charge; that is, from free electrons from some such source as the filament 2. On the other hand, the other three circuits, 6, 6 and 6 are in fact independent for the resumptions' of the normal negative charges upon their photoelectric cathode bodies 3 trons from the cathodes 2. This is, of particular importance, particularly when. I construct m electronic relay .in one of its preferred late not onl acts as a barrier interposed ween the ame'nt'2 and the elements of the hOto-electric 'cou le, but is caused to con itute the wall of t e bulb itself in closing the elements of this thermionic .relay. This will be described more in detail later.

In these circuits 6, 6 and 6, two distinct classifications may be made. In the circuit of 6 the batteries must be so connected as to force an inexhaustible supply of electrons upon the photo-electric ody 3 which can be supplied at such great rate that in this case its otential can-not be lowered ma. terially b tli euit the e ement, the. otential variations of which are employed orcontrolling the potential of the grid, is the anode. In the from the cathode 2. In no instance is this simply by connecting of any free elecorms, namely, that in which the:

e action of light. In this cirother two circuits, Fi the influence of the re of electrons, the batteries, is limited in its recharging effect upon the photo-electric cathode 3 by the high resistance of the leakage resistance 42. If this is physically presout as a part of the circuit, and as has pre- VlOUSl been described, or by the leakage path t rough the thermionic relay itself rov1ded 1ts atmosphere is soft. secon rechargin source of electrons 4, the cathode bodles 0? Figs. 6 and 6, is a conductive flowof electrons 14, which 6' and 6, however, atively infinite source along the wire 15 from the grid receives them as free electrons so iufluencein the rechar ing of the cathode body a current flow, and does not constitute the current pulsations into which I translate light pulsations.

In order that the above and still other connections may be efiective without haw-- mg to change t e construction of the apparatus proper and when it is desired to combme all elements in one unitary structure, I preferably use apparatus as shown in Fig. 6. The body, the filament, the plate, the grid and the anode here are each connected independently with exterior contact 'pins. Contacts 22 and'23 are connected with the grid 14 and with the anode 16 respectivel The desired connections can now be ma e one contact pin with circuits as may be (See, for example, Figs. 6, 6"

another through such desired. and 6.)

It is pertinent here to state that the apparatus described may be varied in many res ects without departing from the scope an the spirit of my invention. For instance, all the parts need not be located within a single bulb. For example the plate 12 may be provided outside of its bulb. Or the plate 12 may be-extended to form part of the bulb wall. It will be clear to anyone skilled in the art that my novel means and combinations of means maybe employed for quite a number of widely different purposes. I may still add that they may be used, inter alia, as a generator of radio frequency alternating currents through. the utilization of anyof the wellknown" hook-ups for that purpose, but with the strength of such radio, frequency alternating currents governed directly by light impulses.

What I claim'as my invention and desire to secure by United States Letters Patent, i's: 1. Means in combination for transforming light impulses into electric current impulses comprising a cathode, a grid and a plate, a plate circuit includin a source of current for the traverse of said electric current impulses; a photo-electric body adapted to be subjected to light impulses; an envelope for maintaining said body in a 00- 180 body operative atm here; provisions tending to reduce and maintain a negative normal potential for said body but themselves inca tential variations to said grid corres nda ing to those which take place on said ody.

2. The combination as characterized in claim 1 and further specified by the fact that a high resistance s connected between said body and said cathode.

8. In combination, a photo-electric couple having an envelope to maintain it in a co- 0 two atmos here and comprising a p oto-electric cat ode-body, adapted-to be sub'ected to light im ulses, and an anode; a cat ode, a grid an a plate; a source of direct current and a leaka e resistance con nected in series with said p oto-electric coule, the negative terminal of said. source having a connection with said. cathode and leading to said cathode-body and the 25 five terminal of said source leading to said anode; and a link-means electrically connesting said cathode-body and said'grid and ads ted to impart potential variations to grid corresponding to those which take place on said body in responseto said light impulses, whereby appreciable corresponding impulses inelectron-flow to said plate are efiected.

4. In combination, a photo-electric cou ple having an envelope to maintainut in a coo rative atmosphere and comprising a cat ode-body, adapted to be sub ected' to light im receive t e electrons shed b said cathodebody; a cathode, a grid an a plate and a plate circuit for the passage of current im- .pi lses; provisions tending to produce and normal potential for said cathode-body; and a link-means electrical] connecting said anode and sa d grid and a apted to impart potential variations to said grid corresponding to those which take place on said anode due to the reception of electrons from said cathode-body.

5; In combination, a photo-electric con ple having an envelope to maintainjt in a coo ative atmosphere and comprising a catl d de-body, ada ted to be subjected to maintain a negative light impulses, an ceive the electrons shed by sai cathodebody; a cathode, a grid and a plateand a plate circuit for the passage of current 1mpulses; provisions tending to produce and maintain a negative normal potentialfor.

said cathode-bod and a link-means ele tricall connecting said anode and said grid and a apted to impart otential variations to said grid correspondm take place on said anode tion of ulses, and an anode a opted to an anode ada' ted to rcto those whichue to the recep electrons from said cathode-body? and a leak resistance connected between said link-means and said cathode.

6. The combination as characterized in claim 4 and further specified by the factthat said ]ink-me ans is a direct conductive connection.

7. The combination as characterized in claim 5 and further specified by the fact that said link means is a direct conductive connection. i

8. In combination a photo-electric couple in a cooperative atmosphere; a currentstrength-controller operating by reason of changes in potential; a link-means electrically connecting one electrode of said photoelectric couple with said current-strengthcontroller and adapted to impart potential variations to said controller corresponding to those which take place on said electrode; and provisions tending to produce and maintain a ne ative normal potential for the cathode 0% said provisions being incapable of maintaining an unchanged normal potential upon that electrode of said photo-electric couple which is electrically connected with said current strength controller.

9. In combination a photo-electric-cathode-body exposable to light variations and in a cooperative atmosphere; a grid which controls a current flow by reason .of potensaid photo-electric couple, but" tial; and a link-means between said catliodebody and said grid to control the potential of said grid by potential changes in said cathode-body; and provisions in addition to said link-means tending to maintain a fixed charge on said cathode-body.

electric cathode-body; and provisions for ex:

posing said photo-electric cathode-body to light impulses, whereby substantially instantaneous 'electro-static potential changes in response to said light impulses are made by the instantaneous liberation of electrons from said photo-electric cathode-body to ef'-.

fect simultaneous potential changes upon said grid which in turn cflects correspond-' ing appreciable current changes in said plate circuit. 7

'11. A method of transforming light varia- 10. Means in combination for transform-- tions into electric current variations, which consists in submittin a photo-electric body,

enclosed by a bulb w iich is exhausted of air to the influence of a stream'of electrons flowin from a source of electrons, subjecting said body .to the action of a variable-exterior source of light, and associating such body with an electric circuit so that the stren tli of the current of such circuit will. be var ed in accordance with the variations of the source of li ht. I 12. A mt 0d of transforming light variations into electric current variations, as claimed in claim 1 in. which the stream of electrons flowi'ng'from said source of electrons is submitted to the governing influence of a body provided; in the path of the said electrons.

13. A method of transforming light variations' into electric current variations, which consists in submittin a 'photo-electricbody enclosed by a bulb w ich is filled with rare;

- arran fied neutral gas to the influence of a stream of electrons flowin from'a source of electrons, subjecting said body to the action of a, variable exterior source of light, and associatin such body with an electric circuit, so that the strength of the current of such circuit will be varied in accordance witlrtlie variations of the source of .light. a

14. Means for transforming light impulses into electric current impulses including a 'bulb, electron emitting means arranged in said bulb and a photo-electric body spaced apart from but associated with saidelectron emitting means so as to be influenced by the stream of electrons emitted from said electron emittin means, such photoelectric body being a apted to be submitted to the action of a variable source of light.

15. Means for transforming light impulses'into electric'current impulses includmg a bulb, an electron emittin means arranged in said bulb, a photo-eectric body spaced apart from but. associated with said electron emitting means so as to be influenced by the stream of electrons emitted from said electron emitting means, such photo-electric body beingadapted to be submitted to the action of a varlable source of light, and a plate member also arranged in said bulb. I

16. Means for transforming light impulses into electric current impulses including a bulb, an electron emitting means arranged in said bulb, a photo-electric bodyspaced apart from but'associated with said electron emitting means so as to be influenced b thestream of electrons emitted from said efiactron emitting means, such photo-electric body being adapted to be submitted to the action of a variable source .of light, a metal plate arranged in said bulb, and a grid also in said bulb.

17. cans for transforming light a..-

pulses into electric current impulses includmg a bulb, an electron emitting means arranged in said bulb, a photo-electric bodys aced apart from but associated with said e ectron emitting means so as to be influenced by the stream of electrons emitted from said electron emitting means, such photo-electric body being adapted to be submitted to the action of a variable source of llght aud individual contacts for the electron emittmgmeans and photo-electric body arranged externally of said bulb. s

18. Means for transforming light impulses into electric current impulses includmg a bulb, an electron emitting means arranged In said bulb, .a photo-electric body spaced apart from but associated with said s aced apart from but associated with said e ectron emitting means so as to be influenced by the stream of electrons emitted from said electron emitting means, such photo-electric body being adapted to be submitted to the action of a variable source of light, a metal plate arranged in said bulb. and a grid also arranged in said bulb and. individual contacts for the electron emitting means, photo-electric body, plate'and grid, arranged externally of said bulb.

20. Means for transforming light impulses into electric current im ulses includ mg a bulb,.a filament arrange in said bulb and a photo-electric body spaced apart from but associated with said filament so as to be influenced by the stream of electrons emitted from said filament, such hoto-ele'c tric body being adapted to be submitted to theaction of a variable source of light.

21. Means for transforming light imulses into electric current im ulses includmg a bulb, a filament arran e in said bulb,

ace apart from but influenced by the stream of electrons emitted from 881d filament, such photo-electric body beingadapted to be submitted to the actionvof a variable source of llght, a metal plate arranged in said bulb, and a grid also arranfid in said bulb.

23. l v I pulses into electric current 1m ulses 1ncludmg a bulb, a filament arrange in said bulb, a photo-electric bod spaced apart from but associated with said filament so as to 1nfluenced .by the stream ofelectrons emitted from said filament, such photo-electric body being ada .ited to be submitted to the action} of a varia lesource of light and individual contacts for the filament and photo-electric body arranged externally of said bulb.

24. Means for transforming light unpulses into electric current impulses includ- -ing. a bulb, a'filament arranger in said bulb,

:r-photo-elcctric spaced apart from but a'fiwociated. with said filament so as to be influenced by the stream of electrons emitted from said filament, such hot0-electr1c body being adapted to be submittedto the action of a variable sourceof light, a plate member also arranged in said bulb,-and individual contacts for the filament, photo-electricbody and plate arranged externally of said bulb.

25; Means for transforming light impulses into electric current 1m ulses 1I'lOll1dmg a bulb, a filament arrange in said bulb, a; photo-electricbod spaced apart from but associated w'ithysait filament-so as to in 3 financed by thestream of electrons emitted fromsaid filament, such photo-electric body being ada' ted tobe submitted to. the action of avaria 1e source of light, a metal plate arranged in said bulb, and individual contacts "for {the filament, photo-electric body,'

4 laige and g rid', arranged externally" of said into electricicurrentimpulses includrngfa bulb electron emitting means arranged in h'oto-elc'tricf body spaced apart fromsaid e ectron, emitting means but exposed to the electrons-emitted by said elec- .tron..emitting-vineans, such photo-electric ;lx dy being adaptedetobe'snbmitted to the action of a va'riable source of light.

' 27 Means for transforming light impulses into electric'current impulses including a bulb, electron emitting means 3 arranged in :said bulb,fa- 'photo-electric.body associated with. said electron emittingmeansso as to be influenced by the stream of electrons emitted therefrom; said-nphoto-electricbody being in the-:forrn of a concave mirror, and

'anelectrode in} the focus of' said mirror.

28. M'ea'ris for transforming light im ulses into/{electric current impulses 'mcludln a bulb,-felectron emitting means arrange in .saidbulb, a photo-electric body associated with said electron emitting means so as to cans for transforming light im-' -6; Meansfor transforming light, impulses be influenced by the stream' of electrons emitted therefrom, said photo-electric body bein in the-form of a concave mirror,.a meta plate within said bulb and a grid also within said bulb, an electrode in the focus of said mirror said photo-electric body hav 'ing a metallic connection with the grid and the electrode having a -metallic connection with the electron-emitting means.

29. Means for transforming light impulses into electric current impulses comprising a bulb, electron emitting means arranged in said bulb, a photo-electric bod exposed to the electrons emitted by said 0 ectron emit-- ting means so asito have a staticpotc'ntial imparted thereto? by said electrons, said. -photo-electric body being adapted to be sub. mitted to a varying'source of light so that the potential thereof imparted thereto by said electrons may be caused to vary in accordauce with the variations in the strength of such light, and means whereby such variations in the static potential of said photo-electric body may cause corresponding variations in the electric current inone ormore circuits.

30. A method of transforming light varia tions intoelectric currentvanations' which comprises submitting a photo-electric body to the potential restoring influence of a source of negative charge capable of -sublstautially completely restoringthe potential U of said photo-electric body after electrons are emitted therefrom in" response to light,

but incapable of rnaintainin the potentialof said photo-electric body w en it is being subjected tolight; subjecting said photoelectric body to the, action of a variable.

source of light and'thereby effecting corresponding potential changes .in said photo electric body; and im arting the controlling effect of said potentia changes in said photoelectric body to the stream of cathode emitted free electrons'of a plate circuit.-

31. Apparatus in combination for transforming light impulses into current impulses comprising the three elements of a therm1on1c"relay-a grid, a cathode/- and a plate; the two elements of a photo-electric [cell-an anode and a cathode-body, walls forming chambers ca able of maintaining a vacuum, one of sai chambers containing said three elements of a thermionic relay and the other of said chambers containingsa'id two elements of a photo-electric cell; leads" and terminal contacts for said three elements of a thermio'nicrelay fixed for socket" niountin at one locality of said walls;'and indepen ent leads for connecting said anode and said cathode-body respectively. with said plate and said grid in a diiferentwalllocality from that of said leads and terminal contacts and by substantially the shortest paths. I p

THEODORUS H. NAKKEN. 

